1. Field of the Invention
This invention relates to a thermal transfer printer using a cassette with a built-in rolled medium such as an ink film.
2. Description of the Prior Art
Loading of an ink film into a printer for printing characters or images has conventionally been put into practical use in a large number of printers and typewriters. As a method of easily loading ink film having a particularly large width are known, such as one disclosed in Japanese Patent Laid-Open No. 67278/1981. This method fits a supply spool for supplying an ink film and a take-up spool for taking up the ink film into the same cassette which connects a plate roller for superposing receiver paper with the ink film at the time of printing to the supply and take-up spools inside the cassette by means of a torque converter. Thus, the ink film is supplied in accordance with the printing operation.
However, the prior art technique described above is not free from problems. For example when an ink film for a plurality of sheets is wound on a spool, it is not possible to determine the status of the ink film, particularly when the ink film cassette is removed from the printer. The remaining quantity of ink film is not recorded and the user of the printer cannot determine the remaining quantity of inked film especially when a plurality of, or a plurality of kinds of, ink film cassettes are used.